


Reflections on the Motive Power of Fire

by simplyirenic



Category: Les Misérables - All Media Types, Les Misérables - Victor Hugo
Genre: Gen, Illustrated
Language: English
Status: Completed
Published: 2013-12-20
Updated: 2013-12-20
Packaged: 2018-01-05 05:48:44
Rating: General Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,653
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1090344
Author URL: https://archiveofourown.org/users/simplyirenic/pseuds/simplyirenic
Summary: <blockquote class="userstuff">
              <p>“Its creator calls it a gas vacuum engine,” said Combeferre over the hellish noise, pronouncing the English words with a certain meticulousness, “though I think this one in particular ought to do more vacuuming."</p>
<p>In which Enjolras learns the perils of having a polymath for a roommate, and Sadi Carnot invites himself along for the ride.</p>
            </blockquote>





	Reflections on the Motive Power of Fire

**Author's Note:**

  * For [bandykullan](https://archiveofourown.org/users/bandykullan/gifts).



**1826**

There were, Enjolras had learned, certain hazards involved with sharing rooms with Combeferre, none of which had to do with the rooms themselves. The rent (eighty francs a month) was reasonable, the location (at the heart of the Latin Quarter) ideal, the landlady (recently widowed, and inclined to spoil her young boarders) more than kind. All things considered, very little to complain about; indeed, they would have been hard-pressed to find better.

The rooms were acceptable; it was the roommate who required getting used to.

Enjolras had known before, of course, of Combeferre’s varied scientific interests. He had thoroughly approved, seeing in him the sort of comforting, steady faith in scientific progress that complemented Enjolras’s fiery passion for social progress. He had thought working and living with Combeferre might temper his own spirit and lend to their cause the sort of quiet wisdom which he expected came with immersion in the _ars scientia_. He had not thought the _ars scientia_ would be so...cluttered.

But Enjolras was willing to adapt. What Combeferre lacked in regard for personal space he more than made up for in companionship, in engaging discourse, and in sheer volume of knowledge. By the end of the first week, Enjolras had learned to navigate the small forest of books and papers which barred his way to their front door without stubbing his toes; by the end of the second, he could comfortably take his dinner while being stared down by the small army of frogs in jars, all in varying stages of development, lined up directly across from him.

Which was why, one afternoon in June, when he ascended the stairs to their shared apartment and found an immense cloud of steam billowing out from underneath the door, he only cracked a faint, resigned smile before opening the door to utter chaos.

The table and chairs which normally occupied the center of the room had been hastily shoved aside, spilling their contents everywhere. A sheet of paper covered in half-decoded hieroglyphs flapped wetly at his feet as Enjolras entered, and two of the frogs had escaped their jars and were currently attempting to extend their escape to the window, which had been cracked open in a vain attempt to provide relief from the steam.

The source of the steam in question stood where the table and chairs had been: an indecipherable contraption made of copper and brass, which clanked and shuddered and threatened to fall apart before his eyes. Pistons pumped frantically above its three cylinders, powering what appeared to be some sort of wheel, and as Enjolras watched, another puff of steam drifted up from its whirring innards.

“--based on what I managed to piece together from the newspaper reports,” came Combeferre’s voice from somewhere within the cloud of steam. “For all intents and purposes, he appears to have based it on Newcomen’s model: hardly a step forward in that regard, but ingenious nevertheless.”

“Ingenious but inefficient,” said another voice, quieter than Combeferre’s, and unfamiliar.

“That is true,” said Combeferre, emerging from the steam with what appeared to be a box of scrap metal, followed closely by a dark-haired man perhaps a few years older. “Though I have yet to determine whether that is a flaw inherent in M. Brown’s design, or simply because I have gotten the cooling system wrong. I assume it is the latter; the articles made no mention of Shooter’s Hill being wreathed in steam--ah, Enjolras! You are back early.”

“Class let out early. What on earth is--,” began Enjolras, but he was forestalled by an unearthly shriek from the machine.

“Its creator calls it a _gas vacuum engine_ ,” said Combeferre over the hellish noise, pronouncing the English words with a certain meticulousness, “though I think this one in particular ought to do more vacuuming. Never mind it, it will be out of the room within the week. Enjolras, may I present Sadi Carnot, lately of the General Staff? He has been advising me on the particulars of this project.”

“Project,” repeated Enjolras, as M. Carnot inclined his head politely and they shook hands.

“It was in the _Times_.” Combeferre set the box down and produced a wrench from its depths. “Not three weeks ago, a Mr Samuel Brown built an engine not unlike this one, attached it to a carriage, and drove it some four hundred feet up a hill in London. I was reminded, when I learned of the event, of M. Carnot’s treatise on the motive power of heat; I wrote to him with the idea of replicating the experiment, he responded with enthusiasm, and here we are.”

“None of which answers the question of why it is presently in our flat,” said Enjolras mildly. “Unless you mean to say you built this engine in a day--which, to be perfectly honest, I might believe.”

“In a week. Did you know,” said Combeferre, as he tightened a bolt, “that the windows of the previous century are poorly equipped to handle sudden exothermic reactions--”

“It exploded,” offered Carnot, who had not uttered a word for the last five minutes.

Combeferre coughed. “Only one of the cylinders exploded,” he said. “The Sorbonne suddenly became a less than ideal habitat for this particular species of engine. I meant to find another for it within the week, but early this morning I was struck with the notion that perhaps Brown’s design might be improved: there is a considerable amount of energy lost in the transfer of the combustion to the engine cylinder, which could be prevented altogether if the combustion were to take place within the cylinder itself, as per Street’s model.”

“Certainly it should reduce the amount wasted overall,” said Carnot, “though I fear too much of it is still lost between the engine’s component parts to render your design feasible.”

“I see,” said Enjolras, who did not. He adjusted his cravat. The day had already been humid; the machine’s intermittent belching increased the temperature in the room to sweltering, but Combeferre did not seem to notice, though his shirt was dripping and his hair was plastered haphazardly across the front of his head. “Well, I suppose I cannot blame you for acting in the, ah, heat of the moment.”

At this, Carnot at last cracked a smile. “I must thank you, monsieur, for lending your friend the use of your room. The engine will be out of your hands as quickly as I can manage it; the _polytechniciens_ , I am sure, will welcome it with open arms.” He paused. “And now, I seem to have misplaced my hat.”

“It is a new pinnacle of human ingenuity,” said Combeferre to Enjolras later that evening, after they had finally located the hat, perched jauntily atop a taxidermied armadillo, and Carnot had taken both hat and leave with a bow. “In England there are trains carrying over seven hundred passengers between cities at a speed of ten miles an hour, daily. Only think of what might be accomplished without the limitations of a rail!”

Enjolras smiled. With the engine silenced and the steam mostly dissipated from the room, it had grown considerably easier to think, and Combeferre’s enthusiasm was proving infectious. “You think there is potential in Brown’s experiment, then.”

“I believe there is.” Combeferre leaned forward, eyes alight. “If Carnot’s theory holds, we might increase the efficiency of the gas vacuum engine to some thirty percent, even without the modifications I proposed. The possible applications in the city alone are endless: omnibuses, for example, powered by the engine, moving at twice their current speed.”

“Steam-powered omnibuses,” mused Enjolras, his smile widening a little, and glanced at the engine. In the warm light of the fire it seemed to him a little less incomprehensible now, its presence more reassuring than baffling. “It is certainly possible. The track may limit man; the omnibus may free him.”

 

**1832**

“It occurs to me now,” Enjolras said one evening, over his copy of _Le Globe_ , “that I never asked what happened to your engine.”

“Sacrificed in the name of progress some two years past,” said Combeferre wryly, not looking up from his microscope. “I believe I saw one of the cylinders supporting the barricade on the Rue Sofflot. I have never gotten around to rebuilding it.”

“The engine, or the barricade?”

Combeferre smiled briefly and a little sadly. He did not state the obvious, though Enjolras heard it anyway: in recent days there had not been time to devote to what had amounted to little more than a hobby--not when there were matters of more import at hand.

“In any case,” Combeferre added, “I can hardly begrudge the _polytechniciens_. It’s not as if we were making much progress, and Carnot has stopped returning my letters. Likely he has other things to occupy his attention now. Why do you ask?”

Enjolras indicated his newspaper. “Evidently there is to be a railway built in Paris. Some of the Saint-Simonians I spoke to this afternoon mentioned it in passing as well; I think the men in charge of the proposal belong to them.”

Combeferre looked up then, a pleased expression flickering across his face. "That’s welcome news. Did they say where?”

“From the Place de l’Europe to Le Pecq.” He paused, and added carefully, “I have never been to Le Pecq.”

Combeferre’s smile slowly widened. “In that case, we will have to go sometime. In two years? Three, perhaps: let us not underestimate bureaucracy.”

“I am only sorry it isn’t a steam-powered omnibus,” said Enjolras, and Combeferre laughed.

“There will be time enough to build one later. It’s a small step, but better late than never, and I can’t find it in myself to complain when I have yet to even see a train with my own eyes.”

“Then I look forward to it,” said Enjolras, and returned his smile. “As for the rest--who knows what the future will hold?”

**Author's Note:**

> -Special thanks to Carmarthen for betaing!
> 
> -Combeferre's domestic habits are inspired partially by tenlittlebullets' headcanon and also by every student of the sciences I have ever had the misfortune to live with. Myself included.
> 
> -Sadi Carnot is widely considered the father of thermodynamics. He published his theory of heat engines in 1824, to relatively little contemporary acclaim, but I think Combeferre of all people would have taken notice. As for why he wasn’t answering Combeferre’s letters: by 1832 his health had declined considerably, and he would succumb to cholera late that August.
> 
> -The Péreire brothers would not submit their plans for the first French railway until September 1832, but I assume they would be talking about it long before then. 
> 
> -The Paris-Saint-Lazare-Saint-Germain-en-Laye line was finally inaugurated in 1837, five years after the June Rebellion.


End file.
